The utility model belongs to the technical field of cotter pin mounting tools of electric transmission and transformation equipment, and discloses a cotter pin restorer. The cotter pin restorer is mainly technically characterized in that the cotter pin restorer comprises an insulation rod and a cotter pin fixing mechanism, the insulation rod is provided with a fixed end, the cotter pin fixing mechanism is provided with a fixed rear base, the fixed rear base is fixed with the fixed end, the cotter pin fixing mechanism further comprises a screw stem fixed with the fixed rear base, a nut is disposed on the screw stem, an 'L'-shaped clamp plate with a folded edge is disposed on the nut, a center axial line of the screw stem passes through the folded edge of the clamp plate, an operator leads a cotter pin to be clamped at the top end of the screw stem and in a clearance on the inner side of the folded edge of the clamp plate by rotating the nut and reversely rotates the insulation rod after achieving a position required to be provided with the cotter pin so as to lead the cotter pin to drop, and then the cotter pin can be mounted on conditions that electric transmission and transformation lines work normally. The cotter pin restorer is convenient in installation and high in reliability, saves time and labor, avoids large quantities of complicated transfer switch required when in power failure, and can repair a defect about ten minutes only.